Incrustation preventive.



UNTTED STATES PATENT OFFICE.

EDVARD HOLM, OF CHICAGO, ILLINOIS.

INCRUSTATION PREVENTIVE.

SPECIFICATION formingpart of Letters Patent No. 699,684, dated May 13, 1902.

Application filed May 17, 1900. Serial No. 16,969- (No specimens.)

T0 aZZ whom, it may concern.-

Be it known that I, EDWARD HOLM, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Incrustation Preventives; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a metallic composition or compound that is more especially lntended for use in steam-boilers and similar steam-generating appliances for preventing incrustation from the impurities contained in the water.

It is well known that nothing but pure water enters into the composition of steam, and it has long been a serious question as to how to dispose of the impurities in water that is to be used in the generation of steam and prevent incrustation and the formation of scale. Unless the water is purified the impurities held in solution or suspension are deposited on the metal surfaces and adhere thereto tena ciously. The thickness of this deposit gradually increases, and as scale is a very poor conductor of heat a large percentage of the products of combustion are lost by its interposition. The boiler is also weakened by the formation of scale, and this has undoubtedly been the cause of many explosions.

The object, therefore, of this invention is to provide means that will prevent incrustation and deposit the impurities from the water loosely in the bottom of the boiler or retain certain particles in suspension, which may then be easily washed out in the usual operation of cleaning out the boiler. The composition also acts to remove scale already formed by softening and loosening it, so that it may be easily scraped or washed out with a hose. When the scale has been of a longtime accumulation and has reached a considerable thickness, the proportions of the composition may have to be varied and a larger quantity used in efiecting the desired result.

The composition consists of zinc, tin, antimony, mercury, and nitrate of silver in about the following proportions: zinc,seven ounces;

tin, four ounces; antimony, three ounces;

grains. These elements are compounded in a molten state and thenmolded or cast into bars of suitable commercial dimensions-say fifteen inches in length by two inches in width and three-fourths of an inch in thickness. These bars may be scored at intervals for convenience in breaking the same up into usable parts.

The proportion of the different elements entering into the composition may be varied in accordance with the nature of the water to be acted upon.

The actual quantity placed in a boiler at a time will be determined by the horse-power. A piece three inches in length and of the other dimensions given will ordinarily be sufficient for boilers rating from ten up to thirty or forty horse-power and will be proportionately increased for larger boilers. The nature of the water may also be taken into consideration, as a little experimenting and use of the composition will determine.

The composition when solidified has the appearance of being a bar of ordinary metal and is very heavy. In practical use it has been customary to suspend a piece of the metal composition on the inside of the boiler, where it can be acted upon by the steam or boiling water, the piece being usually submerged.

It is found by practical working that the water isnot only thoroughly purified by the action and operation of the composition, but the effect on the inclosing boiler-surfaces is such that no impurities of any nature whatsoever will adhere thereto. fect also prevents priming or foaming, which is another great advantage, as the liability of explosions is lessened, and where the steam generated is used for power purposes no gritty substance is carried over with the steam to the injury of the piston, the cylinder, or the valve-surfaces.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

A metallic composition for preventing incrustation in steam-generating appliances, consisting of zinc, tin, antimony, mercury,

The natural ef- In testimony whereof I affix my'signature in presence of two witnesses.

EDWARD HOLM.

L. M. FREEMAN, L. B. OOUPLAND.

eury, and the proportion of the nitrate of silver being less than that of any other element. 

